Low voltage direct current (LVDC) distribution systems are emerging in a number of industrial, commercial, and residential applications. Typically LVDC distribution systems involve the use of many power electronic converters on either the distributed power generation or the electric and electronics load side. An example of industrial LVDC distribution systems is the DC data center. In traditional AC data centers, multiple power conversion stages are required to convert utility AC power to DC load power and to ensure that the power supplied to the servers is not interrupted with battery energy storage. By using a LVDC distribution system some DC data centers have been able to eliminate up to two power conversion stages, improving the energy conversion efficiency of the power distribution system.
For residential and commercial settings, another example of LVDC distribution is a local DC grid connecting DC photovoltaic power generation systems, battery energy storage systems, plug-in electric vehicles, and DC electronics and appliances. Traditionally, photovoltaic cells in photovoltaic power generation systems produce DC power that must be converted to AC power before being distributed across the electrical grid. Batteries supply the electricity to fuel electric vehicles in on-board energy storage applications, or provide the backup power and the load peak shaving/shifting services in stationary storage applications. Consequently, batteries are charged with DC power but need additional AC/DC converters in an AC grid system. Other consumer appliances and electronics (e.g., televisions, computers, monitors, printers, and LED lighting) use DC power and require conversion of the AC power delivered by the traditional AC power distribution system to DC power to function properly. The local DC grid enables the direct use of photovoltaic power with better efficiency and minimal power conversion hardware. The DC plug and socket outlet device connects the equipment, appliances or electronics to the LVDC distribution system and delivers the power for end use.